WEBVTT
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This is College Physics Answers
with Shaun Dychko
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To estimate the number of heartbeats
someone will have in a lifetime,
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we have to make some assumptions,
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and we have to assume that
they will live for 100 years suppose,
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and that the heart rate during the
time alive will be 60 beats per minute.
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And then...
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And then otherwise, this question
involves a lot of conversion.
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We have to convert this time
unit of minutes into years
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so that it cancels with
the 100 years there.
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And we do that by multiplying
by 60 minutes per hour,
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and then multiply by 24 hours per day,
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and then multiply by 365 days per year.
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And technically, there's
365.25 days per year
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because it's a leap year every four years
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so that quarter of a day
happens each year,
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but you know, we're dealing
with approximations here.
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So, there's no sense trying to be
super precise in any of these numbers
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because these numbers
are definitely not precise.
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And this works out to 3.1536
times the end of the 9 beats.
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Now, this can't be precise because
our assumptions are not precise.
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And so, we'll round this
to one significant figure
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of 3 times 10 to the 9 beats.
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So, that's 3 billion heartbeats
in one lifetime.
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And if you get a different answer, well,
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that's to be expected because you might
make different reasonable assumptions
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about the lifetime and the heart rate.
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And so, anything of the same
order of magnitude would be fine.
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And by order of magnitude,
I mean anything multiplied by
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10 to the 9 or even multiplied by
10 to the 8 would be reasonable.